Traditionally in meditation, pillows are round and low, roughly 16 inches in diameter and 3 to 6 inches in height. They are called zafus and are usually filled with a natural material called kapok, but sometimes they are filled with buckwheat hulls. The zafu is designed to support meditators in a position called either Burmese or lotus, depending on the placement of the legs. In either of these positions the legs are crossed in front and the mediator's bottom rests on the edge of the cushion. The cushions frequently grow soft with use and make sitting uncomfortable.
Other supports for meditators are called seiza benches. They generally are made of wood and have a seat roughly 17 inches wide resting on a support on either side some seven inches high. In the seiza position, a person sits kneeling with his or her bottom supported on the bench and with her/his knees resting on the ground.
Due to limiting physical characteristics, which include arthritis, aging, injuries, various illnesses and general stiffness, it is often difficult for a person to assume a comfortable position with existing pillows and benches. The difficulty becomes especially acute during the long and frequent periods of meditation often required in meditation practice centers.
Therefore, there is a need for a pillow which can be adjusted to the physical needs of the user, enabling mediators to sit more comfortably and longer. It is these needs which the present invention solves.
Adjustable pillows are known, but until now adjustable pillows which have been patented are increased in height or width by adding a wedge shaped insert to the interior of the pillow such as described in U.S. Pat. No. 3,775,785 of Mittendorf, wherein wedge shaped portions are added to vary the shape of the pillow. A height adjustable pillow is described in U.S. Pat. No. 5,732,427 of Parnham which includes a pillow which is cut from a block of material that includes a removable insert which can be taken out to decrease the height of the pillow. However such a pillow requires the cumbersome removal of the insert for a decrease in height and does not offer a gradual adjustment.
In addition, U.S. Pat. No. 5,528,784 of Painter discloses an adjustable neck pillow which includes many pillow sections with lateral protrusions which are connected to a central base portion. The height of the pillow is adjusted by adding or removing parallel pillow portions from on top or beneath other portions. In Painter, '784 however, the height of the pillow can only be adjusted by adding or removing one of the laterally extending pillow portions.
Furthermore, U.S. Pat. No. 4,349,925 of Macomber discloses a pillow with a design configuration for a neck holding section. Finally in U.S. Pat. No. 4,959,880 of Tesch, a cushion including cushioning material, such as down, feathers, fibers, balls of fibers, or foam particles or the like, includes a hollow interior with an insert bag which can be filled with the filler materials. Thus the height or the size of the pillow can be adjusted by adding or removing the insert.
However, in Tesch '880 adjusting the height of the pillow requires the actually opening the pillow and removing or adding the insert abruptly adjusting the height of the pillow in a non-gradual manner.
The present adjustable cushion offers many ergonomic advantages. Galen Cranz, Ph.D., discusses the ideal standards for ergonomic seating in her book "THE CHAIR, Rethinking Culture, Body and Design." Ms. Cranz is professor of architecture at the University of California at Berkeley, specializing in the sociology of architecture, and she is a certified teacher of the Alexander Technique for structural realignment of the body. She writes:
"After reviewing all the havoc sitting in chairs wreaks upon the body, it becomes less surprising that this cultural practice could impede overall morphological development . . . . "
"ERGONOMIC CONSENSUS"
"How does the science of ergonomics help us overcome the deleterious effects of chair sitting? Some ergonomic recommendations are straightforward and self-evident, and following them would actually minimize, but never completely eliminate, the damage caused by chair sitting. Many chairs fail to meet at least some of these basic standards. These guidelines are termed "performance guidelines," meaning that the criteria are meant to enhance behavior, and that the measures in inches are not ends in themselves. How many criteria from this simple checklist does your workaday chair violate?"
"CHAIR SEATS SHOULD NOT BE TOO HIGH"
"For conventional right angle seating, the Swedish chair researcher Bengt Akerblom argued as early as 1948 for a lower sear height in order to accommodate the shorter half of the population. Today, the standard seat height for an ordinary task chair with a flat seat is 18 inches from the floor, but that is a distortion for at least half of the population. In other words, it suits some sort of mythical "average" body, which turns out to be a tall male body. So, for all children, most women, and a healthy percentage of men, chairs are too high."
"If a chair is too high, it cuts under the knee, pressing the thigh muscles up from below on the edge of the seat. This forces the muscle tissue to take on a load bearing function for which it was not designed. If you are sitting now, do you feel pressure under your thighs? If so, your veins and arteries cannot circulate blood properly. An easy way to tell if your seat is at the right height is that your heals should reach the ground. Your entire foot, including the heels, should rest securely on the floor or other underpinning. If the heals are pulled up, your thighs are probably being compressed against the front edge of the seat."
"CHAIRS CAN ALSO BE TOO LOW"
"If your knees are higher than your hip sockets, that jams your hip joint, and worse, reverses the natural forward curve of your lower back, stressing the discs. The height issue is further complicated by one of the ideas for seating reform, namely, that one's knees should be lower than one's hips in order to preserve the natural curve in the lower back. In this case, one can "walk" the sit bones out to the very edge of the chair and perch there. Higher is better until the sitter approaches a half-sitting/half standing position,"
"For now, our focus is on traditional chairs. Seventeen inches might be a safe compromise, but multiple sizes or adjustable heights are preferable. Like Goldilocks, you want a chair that is not too high, not too low, but just right."
"THE FRONT RAIL OF THE SEAT SHOULD BE CURVED DOWNWARD"
"The reason for curving the front rail of the chair is to eliminate the sharp edge that might cut into flesh under the knee, called the popliteal region. All ergonomicists agree on this simple rule, but it is violated in chairmaking fairly often. . . . "
"WEIGHT SHOULD BE DISTRIBUTED THROUGH BONES, NOT FLESH"
"When seated, you should be able to feel your sit bones on the seat. That's another way of saying that flesh is not supposed to be loadbearing; bones are. This means that both sitter and designer should avoid deep padding for sitting. An overpadded chair forces the sit bones to rock in the padding rather than make contact with a stable surface, thereby forcing the flesh in the butt and thighs to bear weight. Ergonomics researchers say the padding should be "just right," but they don't explain exactly what number of inches they would recommend at what density and for what weight. I prefer one-quarter-inch padding and find one-half-inch padding okay, but any more than that seems to create instability for the sit bones."
"You should be able to feel the sit bones doing their job-carrying about 60 percent of your weight. (When properly seated, the other 40% is transferred down to the heels, which is why they need to be set comfortably on the floor.) To find your balance of weight internally, sit on bare wood. Rock on your sit bones from front to back about 1/4-1/2 inch. Remember that feeling when buying a chair."
"SPACE BETWEEN SEAT AND BACK IS PREFERABLE TO CONTINUOUS SUPPORT"
"Many ergonomicists agree that there should be some space between the seat and the lower edge of the back of the chair. Without that space, the sacrum and the pelvis are pushed forward. That eliminates the natural curve in the lower spine and makes the spine unstable. If there is no space for our butts, we lapse into C-shaped posture. This is true even in lounge chairs if they don't offer an adequately articulated joint between seat and back for our hips and pelvis."
"Unfortunately, these sensible recommendations, backed up by scientific studies, are ignored by many, many designers. If consumers were to refuse to buy or use chairs that ignored even these criteria, chair design would be reformed remarkably, and there would likely be an enormous benefit for the public health." .COPYRGT.1998, Galen Cranz, Ph.D., W W. Norton and Co., New York, N.Y. pg. 101-104, ISBN No. 0-393-04655-9.
It is these deficiencies in ergonomic chair and cushion structures that the present invention seeks to alleviate.